Electric switch



June 26, 1934. H, A' DO GLA 1,964,563

ELECTRIC SWITCH Filed March 16, 1933 3 Sheets-Sheet 1 June 26, 1934. H.A. DOUGLAS ELECTRIC SWITCH Filed March 16. 1933 3 Sheets-Sheet 2fru/enfor f fczrr CZ. poc ylas f-ZM 771m.-

June 26, 1934. H. A. DOUGLAS ELECTRIC SWITCH- Filed March l6, 1933 3Sheets-Sheet 3 Patented June 26, 1934 UNITED STATES PATENT OFFICEApplication March 16,

19 Claims.

This invention relates to electric switches commonly known as thepush-pull type in which a reciprocable handle is pushed or pulled uponto establish the respective operative positions of the switch.

Among other objects, the invention aims to provide an improved and novelconstruction for this type of switch. More specifically the inventionincludes an economical and positive construction of this type havingthree or more operative positions for a switch which may be employed asa dash switch for automotive vehicles in unitary controlling relationwith the stop-light, parking lights and head lights of the vehicle, forexample.

Other objects and advantages will be apparent from the followingdescription taken together with the accompanying drawings showing anillustrative embodiment of the invention, in which- Figure 1 is anelevational view of the illustrative switch, a mounting therefor beingshown in section;

Figure 2 is an enlarged longitudinal section of the switch of Figure 1taken on the line 2-2 of Figures 4 and 6, and showing differentoperative positions of the switch in full and dotted lines;

Figure 3 is a cross-section taken on the line 33 of Figure 2;

Figure 4 is a cross-section taken on the line 4--4 of Figure 2;

Figure 5 is a partial longitudinal section similar to Figure 2 butshowing still another operative position of the switch and taken on theline 5--5 of Fig. 7;

Figure 6 is a cross-section on a reduced scale taken on the line 6-6 ofFigure 2;

Figure 7 is a similar cross-section taken on the line 77 of Figure 5;

Figure 8 is a similar cross-section taken on the line 8-8 of Figure 2but showing in full lines the positions shown dotted in Figure 2;

Figure 9 is a fragmentary longitudinal section taken on the line 9-9 ofFigure 8 illustrating one of the intaglio portions of the fixedcontacts; and.

Figure 10 is an end view of the switch taken from the bottom of Figures2 and 5 on a reduced scale and showing illustrative circuits associatedtherewith.

Referring in detail to the figures of the drawings, the illustrativeswitch comprises a metallic cup-shaped casing 1 closed by a disc 2 ofsuitable insulating material secured to the casing as by means of tonguecontinuations 3 of the casing received in and clinched within shouldered1933, Serial No. 660,990

notches 4 in the periphery of the disc 2. At its other end the casing 1has a hollow bushing 5 riveted in and communicating with a centralaperture in the end wall 6 of the casing. The bushing 5 may beexternally threaded as at '7 and by means of suitable clamping nuts 8and 9 screwed on to the thread 7, the casing may be clamped to amounting 10 which may be the instrument panel of an automotive vehicle.Desirably a spacing washer 11 is interposed between the nuts 8 and 9.The washer 11 may also be slightly resilient to act as a lock member.

Reciprocable in the casing 1, I have shown a metallic shaft 12 which, inthis instance, is of circular cross-section and has a slide bearing inthe bushing 5. The shaft also has at its other end a reduced extremity13 which has a slide bearing in the central perforation 14 extendingthrough the insulating closure disc 2. The shaft 12 is thus fixed uponan axis of reciprocation substantially coincident with the axis of theeasing. Upon the side of the instrument panel 10 facing the driver ofthe vehicle, the shaft 12 may conveniently have screwed thereon, as at15, the knob 16 of insulating material which may be used as a handle forreciprocating the shaft. To prevent rotation of the shaft it may have alongitudinal groove 1'7 in which is received an internal lug 18 in thebushing 5, these parts acting as keyway and key.

Upon an intermediate reduced portion 19 of the shaft 12 within thecasing 1, I afiix an insulating actuator comprising in this instancethree discs of insulating material such as the two keeper discs 20 and21 and the intermediate spacing disc 22 which are clamped between ashoulder 23 occurring where the intermediate portion 19 of the shaft 5joins the main part of the shaft, and a riveted shoulder 24 which may beturned up at the other end of the shaft portion 19. A facing washer 25which may be of metal is advantageously interposed between the rivetedshoulder 24 and the insulating discs, this washer being desirably of adiameter substantially smaller than the discs and in one position of theswitch, the washer is received in a countersink 26 in the inner face ofthe closure disc 2 surrounding the aperture 14 in which the shaftslides. To prevent rotation of the actuator discs 20, 21 and 22 on theshaft portion 19, this shaft portion is desirably fiattened at its side27 and the apertures 28 in the discs receiving the shaft portion 19therethrough are similarly shaped.

In the insulating actuator comprised by the insulating discs 20, 21 and22, the discs 20 and 21 which are the outer discs, may be relativelythin and the intermediate disc 22 may be somewhat thicker and of smallerdiameter than the outer discs 20 and 21, thus creating an annularperipheral groove 29 in which is disposed a radially resilient metalsplit ring 30 which provides a movable contact for the switch, aspresently described. To prevent rotation of the ring 30 with respect tothe actuator, the ring may have an inwardly directed lug (as by beingbowed inwardly at 31) which is received in a notch 32 in theintermediate disc 22. The ring 30 is of slightly less width than theperipheral groove 29 as determined by the space between the discs 20 and21, spaced abreast by the disc 22, so that the ring is loosely heldwithin the groove and is free to have some moderate radial expansionunder its own resiliency except as restricted by the fixed members nextreferred to, or may be free to shift slightly.

These fixed members which cooperate with the ring 30 are here shown inthe form of a plurality of metallic posts fixed on the insulatingclosure disc 2 and normally insulated one from the other by this disc,the posts being spaced apart in parallel relation within the casing 1about the axis of reciprocation oi the shaft 12 so as to presentsurfaces which restrict the radial expansion of the ring 30. Inaccordance with my invention, these posts include at least three, and inthis case four, fixed contacts 33, 34, 35 and 36 complementary to themovable contact provided by the ring 30. These contacts may beadvantageously formed integrally with terminal members 37, 38, 39 and40, respectively, extending upon the exterior of the casing and eachriveted to the closure disc 2 as at 41. As in the illustrative circuitdiagram shown in Figure l0, the terminal 37 may be electricallyconnected by means of the insulated conductor 370. with the groundedbattery 37b carried in the usual manner by an automotive vehicle; theterminal 38 by means of the insulated conductor 38a with the groundedhead-lights 38b of the vehicle; the terminal 39 by means of theinsulated conductor 39a with the grounded parking lights 39b of thevehicle; and the terminal 40 by means of the insulated conductor 40awith the grounded tail light 402) of the vehicle. These insulatedconductors may terminate in the usual terminal plugs 4.1a which areyieldingly received in suitable apertures in the terminals 37 to 40,inclusive, in accordance with conventional practice.

In addition to the contact members, the posts extending within thecasing may include an abut-- ment post 42, which may be convenientlyriveted as at 43 (Fig. 2) in one of the notches 4, a small sheet offiber or other insulating material 44 being desirably interposed in thisnotch between the riveted metallic end of the post 42 and the tongue 3which is also received in this notch. The post 42, which may not be aslong as the other posts, may be advantageously located opposite theinward bend 21 in the ring 30, so that the grounded corners 31a formedby the inward bend 31 just ride onto the post 42, thus restrictingshifting oi the ring in the Oh position of the switch, as presentlypointed out.

The two outer insulating discs 20 and 21 comprised in the actuator areperipherally notched, as best shown in Figure 4 at 45, to receive theposts and permit the posts to slidingly engage the ring 30. Thus thering normally provides a bridging contact between such of these potts asare electrical conductors, that is the posts 33 to 36, inclusive.

In accordance with my invention, certain of these posts have relief andintagiio portions thereon so staggered longitudinally that the ring 30will be out of contact therewith in certain positions of the switch todiscontinue a circuit therethrough. In the position of the actuatorshown in full lines in Figure 2, and also as shown in the cross-sectionin Figure 6, the ring 30 is in engagement with the contacts 34, 35 and36, since in this position of the actuator the split ring is radiallyopposite, or longitudinally abreast, the relief portions of thesecontacts. As previously ined the inherent resiliency of the ring 31')maintains it in contact with these relief portions. By relief portion, Imean the main portions of the posts which normally engage the splitring. In this position of the actuator, however, the ring 30 beinglongitudinally abreast of, or radially opposite, the intaglio portion 46of the contact 2-3,

out of engagement with this contact and consequently is out ofelectrical engagement with the battery 3%. This therefore constitutesthe off pos ion of the switch. actuator since the contacts 34, 35 and3-6 which are in engagement with the ring 30 describe a triangle whichdoes not include the center of the 30 and the ring is therefore notrestrained at suitable points about its circumference by these contacts.I have accordingly provided the additional abutment post 42, alreadyreferred to, which, with the contacts 34 and 35, describes a trianglewhich includes the center of the ring,

thus guarding against its expansion into engage- 5, and as iown incross-section in Figure '7, the

ring 30 is engagement with the relief portions of the contacts 33, 35and 36, but is out of contact with the intaglio portion 47 of thecontact 34. Thus a circuit is established through the grounded battery3%, terminal 3'7, contact 33, '5

ring 30, and (by means of the contact 35 and terminal 39) through thegrounded parking lights 3% and (by means of the contact 36 and terminal46) through the grounded tail light 40b.

In this position of the actuator the contacts 33, 117

35 and 36 are suitably spaced about the center of the ring 30 torestrict it from expanding into engagement with the intaglio portion ofthe con- In this position of the tact 34 and thus at this time nocircuit is established through the head-lights 381).

Next, when the handle 16 is pulled upon to move the actuator to theposition shown in dotted lines in Figure 2, and as shown incross-section in Figure 8, the ring 30 is in engagement with thecontacts 33, 34 and 36, but is out of engagement with the intaglioportion 43 of the contact 35 and thus a circuit is established throughthe grounded battery 37b, terminal 3''], contact 33, and (by means ofthe contact 34 and terminal 38) through the grounded head-lights 38b and(by means of the contact 36 and terminal 40) through the grounded taillight 40b, but not through the parking lights 3%, for the reasonsalready explained.

It will be noted that one of these contact posts,

gitudinally, which cooperate with the resilient ring 30 to yieldinglydetermine the respective operative positions of the switch. In otherwords, as the actuator is reciprocated, the ring 30 expands andcontracts slightly so as to snap over the ridges 49, and there being twoof these ridges, three operative positions of the switch are thuspredetermined, each of these operative positions being longitudinallyabreast of one of the intaglio portions of the other posts. Axialmovement of the actuator beyond the three positions referred to, is ofcourse positively limited by the wall of the switch casing 1 at one endand the closure disc 2 at the other end. The end wall 17a of the groove1'7 may also act as a stop by being brought into abutment with the lugor key 18. To facilitate movement of the ring 30 over the ridges 49,these ridges are provided with cam surfaces 50 at each side thereof andextending longitudinally of the post. To further facilitate the cammingaction just referred to the longitudinally facing edges of the ring 30may be beveled or rounded as at Although the ring 30 is restrained, asalready described, from substantial expansion radially beyond the reliefportions of the posts, should any slight expansion beyond these points,or shifting of the ring, take place, the relief portions of the postsare also provided with cam surfaces 52 which will cooperate with therounded corners 51 of the ring to contract, or shift the ringsufficiently so that the axial movement of the ring and actuator willnot be hindered but the ring will ride up the cam surfaces 52 and ontothe relief portions of the posts for the purpose explained.

It will be understood that the ring 30 may constitute a relativelystrong spring having very slight expansion and contraction but desirablyhaving sufficient resiliency to make a good electrical contact with theconductor posts, and also to provide rather stiff resistance to movementpast the detents 49 to definitely establish the operative position ofthe switch. The sliding engagement keeps the contact points bright.

In each case, where the effective contact surface of the posts isdiscontinued, as by the intaglio portions referred to, this surface isdiscontinued for an extent longitudinally of the posts equal to theaxial width of the ring 30, and in register with one of the operativepositions of the switch.

The axially extending inner walls of the casing 1 of the switch aredesirably faced with an insulating liner 53 comprising a thin sheet offibrous material, such as paper or the like, to guard against contact ofthe posts with the wall of the casing.

So constructed and arranged, my improved switch affords the advantagesheretofore well known in a switch of the push-pull type, and, inaddition, obviates the less advantageous characteristics of this type ofswitch readily lending itself, for example, to a structure involvingmore than two operative positions. At the same time, in accordance withmy invention, the switch is sturdy in construction and positive inoperation in each of its respective positions.

Having described my invention, I claim:

1. In a push-pull switch, the combination with a reciprocable actuator;of a radially resilient continuous contact bridge carried by theactuator; a plurality of fixed contacts radially disposed about the axisof reciprocation of the actuator, extending parallel thereto, andengageable by the movable bridge contact to be bridged thereby in onereciprocal position of the actuator one of said fixed contacts at alltimes engaged by said bridge contact; and a detent carried by the lastnamed fixed contact cooperating with the movable bridge contact toyieldingly maintain the respective reciprocal positions of the actuator.

2. The structure of claim 1 wherein said last named fixed contactcenters the bridge contact upon the actuator between two other fixedcontacts and wherein there is a cam surface on the detent cooperatingwith the movable contact to compress the movable bridge contact radiallyto permit axial movement of the movable bridge contact past the detent.

3. The structure of claim 1 wherein said last named fixed contactcenters the bridge contact upon the actuator between two other fixedcontacts in the bridging position of the movable contact and there arecam surfaces on the fixed contacts guarding against permanent axialabutment of the fixed contacts and movable bridge contact in axialmovement of the movable bridge contact.

4. In a three position push-pull switch, the combination of a metalliccasing; an insulating closure therefor; a metallic shaft reciprocable inthe casing and having slide bearings in the casing and closure; aninsulating actuator keyed to the shaft; an annular peripheral groove inthe actuator; a metallic ring carried in the groove and providing amovable contact; a plurality of at least three metallic contacts fixedon said closure, said contacts being in the form of elongated postsradially disposed about the axis of reciprocation of the shaft andextending therealong in parallel relation normally in engagement withthe movable contact; and axially staggered intaglio portions on thefixed contacts causing the movable contact to be spaced from the fixedcontact the intaglio portion of which is radially opposite the movablecontact in each axial position into which the movable contact is movedby reciprocation of the shaft.

5. In a three position push-pull switch, the combination of areciprocable insulating actuator; an annular peripheral groove in theactuator; a metallic ring carried in the groove and providing a movablecontact; a plurality of at least three metallic contacts insulated onefrom the other, said contacts being in the form of elongated postsradially disposed about the axis of reciprocation of the actuator andextending therealong in parallel relation normally in engagement withthe movable contact; and axially staggered intaglio portions on thefixed contacts causing the movable contact to be spaced from the fixedcontact the intaglio portion of which is radially opposite the movablecontact in each axial position into which the movable contact is movedby reciprocation of the actuator.

6. In a push-pull switch having three or more operative positions, thecombination with an insulating actuator reciprocable to said operativepositions; of a radially resilient split ring carried thereby providinga movable contact; a plurality of at least three fixed contactsinsulated one from the other, said fixed contacts being in the form ofelongated metallic members radially disposed about the axis ofreciprocation of the actuator and having surfaces normally in engagementwith the movable contact, one of said members having its said surfacediscontinued in radial alignment with one position of the actuatorwhereby the movable contact is disengaged therefrom to discontinue acircuit therethrough; and a pair of axially spaced apart ridges on oneof the members cooperating with the movable contact to yieldinglydetermine the espective positions of the actuator.

'7. In a push-pull switch, the combination with a reciprocableinsulating actuator; of an arcuate movable contact oaried thereby; atleast three fixed contacts insulated one from the other, said fixedcontacts being in the form of elongated lic members radially disposedabout the axis or reciprocation of the actuator and having surfacesnormally in engagement with the. movable contact, one of n nbers havingits said surface discontinued in radial alignment with one position ofactuator whereby the movable contact is disengaged therefrom todiscontinue a circuit therethrough.

In a three position push-pull switch. the combination with an insulatingactuator reciprocable to three operati e positions; of a radiallyresilient split ring carried thereby providing a movable contact; a plusv of at least four elongated metallic members radially disposed aboutthe axis of reciprocation of the actuator and having surfaces normallyin engagement with the movable contact, at lea. three of said membersconstituting fixed contacts insulated one from the ther, each of saidthree members which constitute 11Xd contacts having its said surfacediscontinued in radial alignment with one operative position of theactuator hereby the movable Contact disenga god therefrom to discontinuea circuit therethroi gh, the said four members being so dispos i themovable contact is in engagen ent mth at least three of the said memhersin each opei 1V8 position the actuator and each s three points ofengagement describing a triangle including the axis of reciprocation ofthe actuator.

9. The structure of claim 8 wherein one of the members has axiallyspaced apart ridges thereon cooperating with the movable contact toyieldi leterr ne the respective perative positions structure of claim 8wherein the acas aperiphe 'ial annular groove therein e" in g themovable contact and wherein the ctuator has peripheral notches ther inreceiving he saic members in engagement with the moveble contact.

11. In a push-pull switch, the combination with a reciprocableinsulating actuator; of an arcuate radially resilient movable contactcarried thereby; a plurality of at least four elongated metallic membersradially disposed about the axis of reciprocation of the actuator andhaving surfaces normal 1 in engagement with the movable contact, at lestthree of members constituting fixed coi acts insulated one from theother, each three nenibers which constitute fixed contacts ha", ing itssaid surface discontinued in radial alignr ent with one operativeposition of the actuator hereby the movable contact is disengagedtherefrom to discon "c a circuit therethrough, the four members being sodisposed that the movable contact is in engagement with at least threeor" members in each operative position of the actuator and each saidthree points of engage; ot describing a triangle including the axis ofreciprocation of the actuator whereby the movable contact is restrainedfrom expanding into engagement with the fourth member.

12. In a three position push-pull switch, the combination with ametallic cup-shape casing; of an insulating closure therefor; a bushingin the wall opposite said closure; a reciprocable metallic shaft passingthrough the casing and having slide bearings in the bushing and closure;an insulating actuator keyed to the shaft; an annular peripheral groovein the actuator; a radially resilient metallic split ring carried in thegroove; a plurality of at least four elongated metallic posts fixed onthe closure and radially disposed about the axis of reciprocation of theshaft in spaced insulated parallel relation within the casing;peripheral grooves in the actuator receiving the posts to be normally inengagement with the split ring whereby the latter provides a bridgingcontact between at least three of the posts; axially staggered intaglioportions upon at least three of the posts causing the split ring to bespaced from at least one of the posts each three respective reciprocalpositions of the actuator, one of the posts being in continuousengagement with the ring; and spaced apart annular ridges on the lastmentioned post cooperating with the ring to yieldingly determine thethree respective positions of the shaft.

3. The structture of claim 12 wherein there are carn between the postsand said ridges and between the posts and said intaglio portionsengageable with the split ring to cause axial compression thereof inreciprocation of the shaft.

i l. The structure of claim 12 wherein there are cam aces between theposts and said ridges engageabie with the split ring in reciprocation ofthe shaft.

15. The structure of claim 12 wherein there is a longitudinal slot inthe shaft receiving an internal lug in the bushing preventing rotationof the shaft.

16. The structure of claim 12 wherein the shaft is generally circular incross section and wherein the portion of shaft receiving the actuatorhas a fiat surface mating with a corresponding fiat inner perimeterportion of the actuator to prevent rotation of the actuator on theshaft.

1'7. The structure of claim 12 wherein the split ring is extendedinwardly at one point in its circumference to be received in a notch inthe peripheral groove of the actuator to prevent rotation of the ring onthe actuator.

18. The structure of claim 12 wherein short post is mounted on theclosure to be engage by the split ring in its position nearest theclosure to center th ring on th actuator between two oppositely disposedfixed contacts.

19. The structure or" claim 12 wherein the split ring is extendedinwardly at one point in its circumference to be received in a notch inthe peripheral groove of the actuator to prevent rotation of the ring onthe actuator and wherein a short post is mounted on the closure to beengaged between the inward extensions of the split ring in its positionnearest the closure to center the posed fixed contacts.

HARRY A. DOUGLAS.

